Four predoctoral positions (6 months - 1 year) are available to perform research as part of a doctoral thesis in the Anti-HIV Therapy Group of the Rega Institute of the KU Leuven, Belgium. This group aims at developing new antiviral compounds for the treatment of AIDS patients. The Rega Institute has a world-wide reputation in AIDS research, especially in antiviral drug design, in determination of the mechanism of anti- HIV action of new compounds and in evaluation and follow up of development of in vitro resistance. Recently our research effort has focused on new antiviral targets, namely HN entry and integration. Doctoral research students who have synthesized new compounds can benefit to great extent from the possibility to evaluate the potential inhibitory effect of their compounds against the replication of HIV in cell culture. Students who study compounds with known anti-HIV activity can profit from the identification of the mechanism of action of their compound. Students who study viral entry or viral integration or antiviral drug resistance in general can use our wide collection of established drugs and HIV strains as well as our proprietary novel technology focusing on HIV entry or integration. Doctoral students will be trained in the different aspects of HIV research and anti- HIV chemotherapy. Special attention will be given to the biosafety training (BL-3 for infectious HIV cell culture work). Skills and techniques trained include: cell culture work; virology (titration, microscopy of cytopathic effect, ultra-centrifugation, time-of -addition experiments, drug-resistance selection, p24 ELISA); and chimeric virus technology (CVT) to elucidate the gene responsible for the reduced sensitivity of the selected strain (cloning, PCR, sequencing, transfection). Students will be trained in enzymatic assays (integrase, reverse transcriptase, protease) and cell culture assays based on reporter gene activity measurement (transactivation, Rev, integrase).